Akira Koarai

Macrophages increase in number and are highly activated in chronic obstructive pulmonary disease (COPD). Muscarinic receptor antagonists inhibit acetylcholine-stimulated release of neutrophilic chemoattractants, suggesting that acetylcholine may regulate macrophage responses. Therefore, expression and function of components of the non-neuronal cholinergic system in monocyte-macrophage cells was investigated. RNA was isolated from monocytes, monocyte-derived macrophages (MDMs), lung and alveolar

These data demonstrated that 25-HC augments the release of IL-8 and IL-6 via NF-κB signalling pathway and enhances the release of IL-8 and IFN-β after stimulation of TLR3 in airway epithelial cells. 25-HC may be involved in the neutrophilic airway inflammation through the stimulant effect of IL-8 and IL-6 release and also potentiate the TLR3-mediated innate immunity in airway diseases.

Virus infections are a major cause of chronic obstructive pulmonary disease (COPD) exacerbations. Recently, Toll-like receptor 3 (TLR3) has been demonstrated to react to double-stranded RNA (dsRNA) and to be involved in the immune responses after viral infections. In the present study, we examined whether oxidative stress, which is involved in the pathogenesis of COPD, enhances the responses of TLR3 in airway epithelial cells. The effect of hydrogen peroxide (H(2)O(2)) on the release of IL-8 fro

Inhaled bronchodilator treatment with a long acting muscarinic antagonist (LAMA) reduces symptoms and the risk of exacerbations in COPD and asthma. However, increasing evidence from cell culture and animal studies suggests that anti-muscarinic drugs could also possess anti-inflammatory effects. Recent studies have revealed that acetylcholine (ACh) can be synthesized and released from both neuronal and non-neuronal cells, and the released ACh can potentiate airway inflammation and remodeling in a

Histamine has a variety of airway actions and is considered to be an important mediator in asthma. This study examined the role of endogenous histamine in allergic airway eosinophil recruitment and hyperresponsiveness using L-histidine decarboxylase gene knockout mice. Histamine levels of the airways in L-histidine decarboxylase knockout mice were largely diminished compared with wild-type mice. Inhalation challenge with ovalbumin (OVA) in OVA-sensitized wild-type mice caused eosinophil accumula

PROSPERO; CRD42020191978.

Nitric oxide (NO) shows proinflammatory actions mainly via reactive nitrogen species (RNS) formation through superoxide- and peroxidase-dependent mechanisms. The purpose of this study was to examine the role of inducible NO synthase (iNOS) in RNS production, airway hyperresponsiveness, and inflammation after allergen challenge. Ovalbumin (OVA)-sensitised, iNOS-deficient and wild-type mice were used. RNS production was assessed by nitrotyrosine (NT) immunoreactivity in the airways. Airway inflamm

Nitrative stress is thought to be involved in the inflammatory process in COPD airways, and the alveolar nitric oxide concentration (CAlv) has been reported to be increased. However, the CAlv levels are also regulated by gas diffusion at alveolar sites. The aim of the study was to assess the relationship between the CAlv and pulmonary function in COPD patients, while taking into account the lung diffusion capacity. Twenty stable COPD patients (GOLD stage1/2/3/4 = 6/8/6/0) and 16 healthy subjects

(PROSPERO: CRD42019144764).

These data suggest that cigarette smoke augments the expression and responses of TLR3 in human macrophages, and this may contribute to neutrophilic airway inflammation and parenchymal destruction in the lungs of smokers and patients with COPD.